Might want to plug your mufflers too. I fired up my AH Sprite the other day and about 2 cups of bird seed blew out the back.
Back in the 80s, parked my Honda 750F in a barn for a few years. When I went to start it, checked the spark/fuel then proceeded to crank it on a car battery. Crank crank crank crank....on and on and no start. WTF....lets keep going....crank crank crank and KABOOM....it started, went right up to about 10,000 RPMs and showered the driveway with mouse shit.:huh Ran just fine afterwards....!
Another vote for the electronic gizmos at Home depot. Friend has used them in his basement with good success. I've heard the dryer sheets work, but havent had to try them. Although I just found the cabin filter (flat) in my Tacoma chewed up. The bastards better not have gotten into the wiring.
Just found another place the little buggers like to stash stuff. I was doing some wiring under the seat on my '71 R75/5 today and discovered the top frame tube under the tank was full of bird seed. The real puzzlement is where in the hell they're getting the seed? This could also be the source of my turn signal problems. Looks like I'll be pulling the tank to look for nibbles in the wiring.